Field of the Disclosure
The disclosure relates to a display technology.
Description of the Related Art
Display devices (e.g., liquid-crystal displays (LCDs), active matrix organic light-emitting displays (AMOLEDs)) are widely employed in electronic products, such as notebook computers, personal digital assistants (PDAs), electronic books, projectors, and mobile phones.
Display panels typically employ thin film transistors (TFTs) as a switching element in a pixel region. Additionally, a complementary metal oxide semiconductor (CMOS) circuit composed of TFTs is also employed in a peripheral circuit (i.e., driving circuit) region. Such elements are classified as amorphous silicon (a-Si) TFTs and poly-silicon (poly-Si) TFTs according to the active layer materials used. Compared with a-Si TFTs, poly-Si TFTs have the advantages of high carrier mobility and high driving-circuit integration and are often used in applications that require high-speed operation. Thus, low temperature poly-silicon (LTPS) is a novel application for a display technology.
The TFTs that serve as switching elements of the pixel region may have a top gate structure or a bottom gate structure. In cases where the display panel has TFTs with a top gate structure, light emitted from the backlight module is applied to the active layer under the gate through the bottom substrate (e.g., TFT substrate) of the display device, generating a light leakage current in the active layer. In order to address this problem, a light-shielding layer is disposed under the active layer. Such a light-shielding layer cannot effectively block the scattering light from the backlight module, however, and therefore the electronic properties of the TFTs cannot be maintained.
Accordingly, there is a need to develop a display panel that is capable of effectively blocking light applied to the active layer under the gate, thereby improving or maintaining the electronic properties of the TFTs.